*{
    margin: 0;
    padding: 0;
}
button{
    outline: none;
}
.contentdiv{
}
#maindiv{
    width: 320px;
    height: 568px;
    background-image:url(image/background_1.png) ;
	position: relative;
	overflow: hidden;
}

#maindiv img{
    position: absolute;
    z-index: 1;
}